Sterility and sexual impotence have been observed in chronic alcoholics for many years. The social impact of alcohol-induced infertility is of great magnitude; especially in the case of the chronic alcoholic whose drinking problem had started during adolescence (i.e., sexual development). The first objective is to develop and characterize an animal model (the mouse) which describes the acute and chronic effects of ethanol upon male fertility. The level of ethanol and time of exposure to ethanol required for maximal injury to the male reproductive tract will be determined. Fertility will be assessed by conducting both in vivo and in vitro fertilization experiments. Other indices of male reproductive tract function will also be evaluated, such as spermatogenesis, spermatozoa transport and maturation, accessory sex gland secretions, and spermatozoa morphology and motility. The animal model will be used to determine that stage of sexual development most sensitive to ethanol as a gonadal toxin. Possible mechanisms of ethanol-induced infertility will be evaluated. This will be accomplished by determining the reversibility of gonadal damage (spontaneous, and that achieved with therapy; e.g., hormonal vitamin A, or zinc). Information concerning the reversibility and the possible prevention of ethanol-induced infertility may provide the basis for clinical treatment of individuals who would otherwise be sexually mature and fertile, but as a result of chronic ethanol ingestion, suffer from sterility, a condition which may persist for years following the cessation of alcohol consumption.